1. Field of the Invention
The present invention relates to an autonomous driving vehicle system.
2. Description of Related Art
Conventionally, as described in Japanese Patent Application Publication No. 2014-085711 (JP 2014-085711 A), a brake control device is known that includes an arithmetic unit that calculates the time to collision based on the relative distance and the relative speed between the vehicle and a following vehicle and a warning unit that issues a warning to the following vehicle based on the comparison between the time to collision and the warning threshold.
According to the conventional technology described above, it may be difficult to know the distance and speed relative to the following vehicle, for example, when the vehicle turns right or left at an intersection or travels through a curve. This sometimes results in an inappropriate warning to the following vehicle. On the other hand, recent advances in the development of an autonomous driving vehicle make it possible to know more exactly the surrounding environment of the vehicle, leaving room for improvement in a warning to the following vehicle.